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Lamprocyclas margatensis (Campbell and Clark, 1944)

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Shell fairly large, stout (approximately twice as long as maximum diameter), bell-shaped; apical horn hyaline, stout (10°), with four wide, triangular blades which run down sides of cephalis below it, its tip sharp; cephalis generally narrow conical (33°), sometimes decidedly asymmetrical and with cervix about 0.35 maximum diameter, length about same as diameter at base; thorax strongly (apically truncate) subhemispherical, thoracic maximum diameter only a little less than that of greatest width of shell, and length about 0.5 that amount; thoracic stricture marked by an internal transverse septum; abdomen laterally (and strongly) convex, maximum diameter reached at or near its middle, below this level shell contracts quickly to squarely truncated aperture; apertural margin about 0.82 maximum diameter in diameter, its margin with about a dozen, divergent, subequidistant, distally sharpened, strong, spikelike teeth; wall fairly thick save distally where it is thinner, dull gray; pores of cephalis 25 or more, fairly well defined in transverse rows, well separated, circular, quite large, of thorax somewhat larger but otherwise rather similar to those above, of abdomen larger again, perhaps 200, all subcircular and less deeply set than in thorax, otherwise pore characters similar to those above. Length, total, 240µm; diameter, maximum, 120µm, of largest pores, as much as 22µm.
Calocyclas margatensis differs from rather similar C. hannai, in being shorter, somewhat stouter, with larger abdominal pores, and in very different apertural characters including, especially, fewer and larger spikelike radial apophyses.
(Campbell and Clark) 1944











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